Senate, and the house of representatives
The correct answer is actually D - Spying.
The reason why D is the correct answer is because during those times, musicians could be invited to parties, balls, and festive occasions that were hosted by one family or another family or nobility or any other important group of people who could pay them a hefty sum to tell them what another family was doing and vice versa. That is why their job offered them the opportunity to work as part-time spies.
The correct answer is A) it crippled the confederate war effort in the wake of the destruction.